Peel the eggplants, if desired, and chop them into bite-sized cubes. Transfer them to a strainer set over a bowl and toss with a tablespoon of salt. Let the eggplant sit while you prepare the rest of the ingredients.

Dice the onions and roughly chop the peppers, zucchinis and tomatoes into bite-sized pieces. Mince the garlic. The vegetables will be cooked in batches, so keep each one in a separate bowl.

Warm a teaspoon of olive oil in a large Dutch oven or pot over medium-high heat. Add the onions and a generous pinch of salt. Sauté until the onions have softened and are just beginning to brown, about 10 minutes. Add the peppers and continue cooking until the peppers have also softened, about another 5 minutes. Transfer the onions and peppers to a clean bowl.

Add another teaspoon of oil to the pot and sauté the zucchini with a generous pinch of salt until the zucchini has softened and is beginning to brown, about 5 minutes. Transfer the zucchini to the bowl with the onions and peppers.

Rinse the eggplant under running water and squeeze the cubes gently with your hands to remove as much moisture as possible. Warm two teaspoons of oil in the pan and sauté the eggplant until it has softened and has begun to turn translucent, about 10 minutes. Transfer the eggplant to the bowl with the other vegetables.

During cooking, a brown glaze will gradually build on the bottom of the pan. If it looks like this glaze is beginning to turn black and burn, turn down the heat to medium. You can also dissolve the glaze between batches by pouring 1/4 cup of water or wine into the pan and scraping up the glaze. Pour the deglazing liquid into the bowl with the vegetables.

Warm another teaspoon of olive oil in the pan and sauté the garlic until it is fragrant and just starting to turn golden, about 1 minute. Add the tomatoes, bay leaf, and whole sprigs of thyme. As the tomato juices begin to bubble, scrape up the brown glaze on the bottom of the pan.

Add all of the vegetables back into the pan and stir until everything is evenly mixed. Bring the stew to a simmer, then turn down the heat to low. Stirring occasionally, simmer for at least 20 minutes or up to 1 1/2 hours. Shorter cooking time will leave the vegetables in larger, more distinct pieces; longer cooking times will break the vegetables down into a silky stew.

Remove the bay leaf and thyme sprigs. Just before taking the ratatouille off the heat, stir in the basil. Sprinkle the extra basil and a glug of good olive oil over each bowl as you serve.

Leftovers can be refrigerated for a week or frozen for up to 3 months. Ratatouille is often better the second day, and it can be eaten cold, room temperature, or warm.